It's entirely unclear to me why the Republicans have decided that PR is unwinnable for them. I had thought that the hurricane that forced tens of thousands of Puerto Ricans to Florida would be crushing to the GOP. Turns out that the Puerto Ricans have been pretty close to 50/50, last I checked.
Yeah, DC would likely be the most lopsided state in the country for the foreseeable future, but the GOP has only itself to blame for that. And anyway, it's not as if states like Wyoming are competitive. The reason that the sparse population of the Big Sky areas -- two Dakotas, Montana, Idaho, Wyoming -- was that Congress was seeking a) political advantage; and b) graft opportunities.
But of course, Mitch McConnell is congenitally incapable of thinking about any principle at all, or even long-term political thinking. 100% of his behavior is predicted by considerations about the next election.